UCSD, PCA & NEES BLIND PREDICTION CONTEST Introductory Remarks
description
Transcript of UCSD, PCA & NEES BLIND PREDICTION CONTEST Introductory Remarks
UCSD, PCA & NEESUCSD, PCA & NEESBLIND PREDICTION CONTESTBLIND PREDICTION CONTEST
Introductory RemarksIntroductory Remarks
Robert Bachman, S.E.Convener
REBachman Consulting Structural Engineers
Test Facility and Test Structure Test Facility and Test Structure
7 Story full-scale building slice
Reinforced concrete structural wall
NEES Large High- Performance Outdoor Shake Table at UCSD’s Englekirk Structural Engineering Center
Outline of this SessionOutline of this Session
Description of Test Facility, Design of Test Structure and Testing Program and Discussion of Test Results
Overview of Blind Prediction Contest, Entries and the computer platforms they used
Comparison of Range of Predicted Values with Measured
Announcement of Winners
Presentation by Contest Winners of Approach Used
DESCRIPTION OF TEST DESCRIPTION OF TEST PROGRAM PROGRAM
Marios Panagiotou, JosMarios Panagiotou, Joséé I. Restrepo, I. Restrepo, Joel P. Conte and Robert EnglekirkJoel P. Conte and Robert Englekirk
Department of Structural EngineeringDepartment of Structural EngineeringUniversity of California, San DiegoUniversity of California, San Diego
Two-phase Project funded by the Englekirk Structural Engineering Center Board of Advisors
Yehuda Bock, SIO, Payload Project PartnerJ.E. Luco, SE UCSD, Payload Project Partner and
Advisor
Ozgur Ozcelik, Graduate StrudentBobak Moaveni, Graduate Student
The assistance of NEESinc, NEESit, NSF, Technical Staff at ESEC and of Paul Somerville (URS Corp.) are greatly appreciated
AcknowledgmentsAcknowledgments
Englekirk Board of AdvisorsEnglekirk Board of Advisors
ObjectiveObjective
Verify the seismic performance of medium rise reinforced concrete wall building designed for lateral forces that are significantly smaller than those currently specified in building codes in United States
Los Angeles
UBC 97: Seven story buildingResidential, multi-wall structure
– Sc soils
– Site less than 2 km from B fault
– Sv = 55 in./sec.V = 0.29 W Base Shear
Displacement-based DesignDisplacement-based Design
Two performance levels:
Immediate occupancy in frequently occurring earthquakes
Limited yielding (1% tensile strain maximum) Limiting interstory drift ratio
Life-safety in rare earthquakes (10% in 50) Tensile strains less than 5% compressive strain less
than 1%
Displacement-based DesignDisplacement-based Design
Based on initial stiffness and an effective first mode mass
Direct use of the Displacement Response Spectra for elastic response
Considers the relationship between inelastic-elastic response of SDOF (Miranda – 90 percentile)
Definition of curvature and displacement ductility– Strain limits for concrete and reinforcement– Foundation flexibility
V = 0.15 W Base Shear
Capacity DesignCapacity Design
To guarantee the desired performance at the Life-prevention level
Explicit selection of a mechanism of inelastic deformation
Explicit recognition of effects caused higher modes of response
Larger than forces obtained from DBD analysis (1st mode!)
Larger floor accelerations
Test StructureTest Structure
7-story building slice with cantilever wall as the lateral force resisting system
Tallest building structure ever tested on a shaketable
Single axis of input ground motion in the plane of the wall
Cantilever web wall
Phase 1 Testing: 12 ft. long rectangular wall
Phase 2 Testing14 ft. 7 in. long T-wall
63’-
0”
21
m
Flange wall
PT wall
Gravity columns
Design Summary & DetailingDesign Summary & Detailing
l = 0.44% t = 0.31% v = 1.36%
Web Wall Level 1
12’-0” (3.6 m)
8” (204 mm)
6” (152 mm)
l = 0.60% t = 0.31% v = 0
Web Wall Level 2
Design Summary & DetailingDesign Summary & Detailing
Aimed at Construction optimization– 1 reinforcement curtain in the wall’s web on level 1– Well confined wall ends
High-strength Baugrid electro-welded confinement reinforcement at wall ends
– 1 reinforcement curtain on levels 2-7– Tunnel form construction– Concrete with specified compressive strength of
f’c = 4 ksi (28 MPa)
Test RegimeTest Regime
Testing at the NEES@UCSD Large High-Performance Outdoor Shake Table between October 2005 and January 2006
Structure tested under increase intensity historical earthquake records and with low-intensity band-clipped white noise in between earthquake tests
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0t (sec)
ag
(g
)
Sf-vnuy-lgn
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0t (sec)
ag
(g
)
Sf-vnuy-tr
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0
t (sec)
ag
(g
)
Nor-whox-lgn
-1.0
-0.8
-0.6
-0.4
-0.20.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0t (sec)
ag
(g
)
Nor-Sylmar-360
EQ1EQ1
EQ2EQ2
EQ4EQ4
EQ3EQ3
Time (sec)
Acc
eler
atio
n (
g)
0 20
Acceleration Response Acceleration Response SpectraSpectra
0.0
0.5
1.0
1.5
2.0
2.5
0.0 0.5 1.0 1.5 2.0 2.5 3.0T (sec)
Sa
(g)
WN2%gWN3%gWN5%gEQ1EQ2EQ3EQ4
=5%
Design spectra
SensorsSensors
600+ sensors deployed on the building, shake table and surrounding soil– DC Coupled Accelerometers– Displacement transducers– Strain gauges– Load cells– Oil pressure transducers
First time use of 50Hz, 3 mm resolution, real-time GPS displacement sensors
17 videos feeds streamed through NEEScentral
Building’s Response to Sylmar Building’s Response to Sylmar Earthquake EQEarthquake EQ44
Performance levels anticipated were met:– Cosmetic damage at the base of the wall– Reinforcement strains reached 2.7%– Peak roof-drift ratio was 2.1%– Residual crack widths less than 1/20th of an inch– Negligible residual displacements (1/2 in. at the roof )
The building slice could perhaps not be immediately “occupied” but only required minimum repairs
Data Curing & Archiving Data Curing & Archiving
Significant amount of data has been collected and is being reduced
All data and metadata will be archived in the NEES Data Repository and will be made available to all NEES users and researchers
BLIND PREDICTION CONTESTBLIND PREDICTION CONTESTScoring, Comparison of Predicted vs Scoring, Comparison of Predicted vs Measured Quantities and WinnersMeasured Quantities and Winners
Robert Bachman, S.E.Convener
REBachman Consulting Structural Engineers
Overview of ContestOverview of Contest
Web site set up – included links to test structure data, test motions, contest rules, input sheet and questions/answers
NEES email addresses set up for Q/A and entries
Contest announced March 10th via electronic communications (PCA, NEES, the NSF EQ Centers, EERI), Structural Engineers Associations – and personal communications
Q & A posted periodically on web site
Entries were due electronically May 15th
Winners notified by May 25th
Basic Contest RulesBasic Contest Rules
Goal – predict responses by analysis - compare with measured
3 Categories of teams – Winner PCA Award of $ 2500 per team 1. Undergraduates 2. Researchers/Academics 3. Engineering Practitioners
Predict responses for 4 levels of earthquakes – responses included displacements, drifts, shears, moments, accelerations throughout the structures and vertical strains near base.
Entries judged by determining error in each type of response Lowest error awarded points. Sum points. Largest sum winner
The entries were handled confidentially – folks at UCSD did not know who submitted what entries. Relative ranking confidential.
Scoring Procedure - Mean Square root error index
Ai : measured (actual) response quantity
Pi : predicted response quantity
Interstory Residual Team i M i V i di ü i / g drift ratio drift ratio*
1 4 1 8 4
8
2 0 0 2 8
4
3 2 8 4 2
2
4 1 4 1 1
58 2 0
0
0
1
Team score
8
2
1
4
0
16
19
10
12
33
Total points
Interstory Residual Team i M i V i di drift ratio displacement
1 0.593 0.844 0.3771.228 0.514
0.294
2 0.684 0.984 0.656 1.920 0.494
0.445
3 0.653 0.492 0.454 1.923 0.585
0.584
4 0.656 0.576 0.823 1.298 0.629
5 0.574 0.696 1.096 3.173 0.633 0.799
0.604
a i
2
i i
i
A Pmsre
A
Entries / Computer PlatformsEntries / Computer Platforms 21 total entries/ 8 countries Undergraduates – 2 teams / 2 countries Countries – Italy and US Computer Platforms – Etabs and SeismoStruct Researchers/Academics – 11 teams / 8 countries Countries – Canada, France, Italy, Mexico, New Zealand, Slovenia,
Taiwan, US Computer Platforms: Abaqus, Canny, Column, Fedeas Lab, Narc2004,
OpenSees, Ruaumoko, Sap 2000 Engineering Practitioners – 8 teams / 2 countries Countries – New Zealand and US Computer Platforms: Adina, ANSR-II, Hand Calculator/code formulas,
OpenSees, PC-ANSR, Ram Perform 3-D
Undergraduate EntriesUndergraduate Entries
Italy – Laura Quaglini
Advisor – Dr. Rui Pinho
University of PaviaUS – Michael Billings, Soyoon Lee and
Evan Peterman
Advisor – Prof. Ansgar Neuenhofer
Cal Poly San Luis Obispo
Researcher/Academic EntriesResearcher/Academic Entries Canada – Alireza Ahmdina and Carlos Ventura France – Stephane Grane, Panagiotis Kotronis and
Jacky Mazars Italy/US – Paolo Martinelli and Filip Filippou Mexico – Mario Rodriquez, Roque Sanchez and
Miguel Torres New Zealand – Dion Marriot, Kam Yuen Yuen, Stefano
Pampanin and Athol Carr Slovenia – Matej Fischinger, Peter Kante and Tatjana
Isakovic Taiwan – Kuang-Yen Liu US/SUNY Buffalo – Methee Chiewanichakorn and Amjad Aref US/Univ of Washington – Blake Doekper, Laura Lowes and Dawn
Lehman US/Univ of Missouri at KC – Kavitra Deshmukh, Ganesh
Thiagarajan, Thomas Heausler US/Iowa State University – Jon Waugh and Sri Sritharan
Engineering Practitioner EntriesEngineering Practitioner Entries
Nikolay Doumbalski, MMI, Oakland, CA Rick Drake, JSDyer, Anaheim, CA Mahmoud Hachem, Emeryville, CA Jimin Huang, HDR Engr, Minneapolis, Minnesota Trevor Kelly, Holmes Consulting Group, New Zealand Bruce Maison, EBMUD, El Cerrito, CA David Nilles,PE. SE., Washougal, WA Jianxia Zhong, Y.L. Mo, Paul Jacob and Turel Gur mostly
from MMI in Houston, Texas
Selected Comparison of Selected Measured Selected Comparison of Selected Measured versus Predicted Responses versus Predicted Responses
(Top 4 in Researcher/Academic and Engineer (Top 4 in Researcher/Academic and Engineer Practitioner Categories) Practitioner Categories)
Blind Prediction Results - EQ3 - Shear Force EnvelopeFirst 4 teams of each category
0
1
2
3
4
5
6
7
0 50 100 150 200 250 300 350
Shear Force (kips)
Flo
or
Measured
Blind Prediction Results - EQ3 - Total Acceleration Envelope First 4 teams of each category
0
1
2
3
4
5
6
7
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3
Total Acceleration (g)
Flo
or
Interstory Drift Ratio
Blind Prediction Results - EQ3 - Shear Force EnvelopeFirst 4 teams of each category
Flo
or
Measured
Blind Prediction Results - EQ4 - Interstory Drift Ratio EnvelopeFirst 4 teams of each category
Interstory Drift RatioF
loo
r
Blind Prediction Results - EQ4 - Relative Lateral Displacement Envelope - First 4 teams of each category
0
1
2
3
4
5
6
7
0 2 4 6 8 10 12 14 16 18Relative Lateral Displacement (in)
Flo
or
Measured
Blind Prediction Results - EQ4 - Interstory Drift Ratio EnvelopeFirst 4 teams of each category
1
2
3
4
5
6
7
0.000 0.005 0.010 0.015 0.020 0.025 0.030Interstory Drift Ratio
Flo
or
Measured
And the Winners Are –And the Winners Are –Drum Roll Please !Drum Roll Please !
Undergraduate Team WinnerUndergraduate Team Winner
Researcher/Academic Team winner Researcher/Academic Team winner
and Engineer Practitioner winnerand Engineer Practitioner winner
Cal Poly San Luis Obispo represented by Michael Cal Poly San Luis Obispo represented by Michael
BillingsBillings
University of Ljubljana, Slovenia University of Ljubljana, Slovenia
represented by Matej Fischingerrepresented by Matej Fischinger
Mahmoud Hachem of Mahmoud Hachem of Wiss, Janney, Elstner, Emeryville, CaliforniaWiss, Janney, Elstner, Emeryville, California